Method of reducing water spotting and oxide growth on a semiconductor structure

ABSTRACT

The present invention relates to a method of cleaning and drying a semiconductor structure in a modified conventional gas etch/rinse or dryer vessel. In a first embodiment of the present invention, a semiconductor structure is placed into a first treatment vessel and chemically treated. Following the chemical treatment, the semiconductor structure is transferred directly to a second treatment vessel where it is rinsed with DI water and then dried. The second treatment vessel is flooded with both DI water and a gas that is inert to the ambient, such as nitrogen, to form a DI water bath upon which an inert atmosphere is maintained during rinsing. Next, an inert gas carrier laden with IPA vapor is fed into the second treatment vessel. After sufficient time, a layer of IPA has formed upon the surface of the DI water bath to form an IPA-DI water interface. The semiconductor structure is drawn out of the DI water bath at a rate that allows substantially all DI water, and contaminants therein, to be entrained beneath the IPA-DI water interface. In a second embodiment of the present invention, chemical treatment, rinsing, and drying are carried out in a single vessel. In a third embodiment of the present invention, a retrofit spray/dump rinser with a lid is used for rinsing and drying according to the method of the present invention.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates to drying semiconductor structures. Moreparticularly, the present invention relates to the minimization of waterspotting and of oxide growth that are experienced on semiconductorstructures during chemical treatment steps, deionized (DI) water rinsesteps, and drying steps. Examples of minimization of water spotting andof oxide growth are given for an HF rinse process in which the steps ofDI water rinsing and drying are combined

2. The Relevant Technology

Producing a substantially impurity-free semiconductor structure is anongoing challenge during fabrication of operable integrated circuits andother microelectronic devices. During fabrication, several operationsare completed with a chemical treatment such as a polysilicon etching, aphotoresist stripping, an RCA cleaning, or a buffered oxide etching(BOE). Following a chemical treatment, rinsing the structure to removetreatment chemicals is required.

Following a chemical treatment such as an HF rinse cleaning, asemiconductor structure is typically transferred to a vessel for a DIwater rinse and then to a dryer to be dried. With each transfer of thesemiconductor structure during fabrication between processing vessels,the possibility of contamination increases and, with that, also thelikelihood of lower process yield. In chemical treatments ofsemiconductor structures that result in exposed hydrophobic surfaces,the possibility of oxidation and particle contamination is high.

During an HF-last rinse of a semiconductor structure with exposedsilicon, for example, a significant number of (Si)2═O bonds are changedto Si—H bonds. About ten to twenty percent of the changed bonds,however, are Si—F instead of the preferred Si—H. During the industrystandard DI water rinse that follows most chemical treatments, the Si—Fbonds in this example are easily washed off, and oxidation ofsemiconductor materials, such as silicon, occurs while transferring thesemiconductor structure from a rinsing vessel to a drying vessel.Oxidation can occur both during the transfer to the drying vessel andwhile the semiconductor structure resides in the drying vessel prior todrying.

Before the semiconductor device is moved to the next fabrication phase,substantially complete drying must be accomplished because any waterthat remains on the surface of a semiconductor structure has thepotential of interfering with subsequent processing. Drying can beaccomplished in spin-rinse dryers (SRDs), Marangoni dryers, axial dryersand others used in the art.

Various drying techniques such as spin drying also cause water spotting.During spin drying, water spotting droplet tracks are left on thehydrophobic faces of the semiconductor structures. These water spottingtracks are formed from slight impurities contained in the DI waterdroplets. Water spotting is caused due to the hydrophobic nature of thecleaned silicon and other surfaces such as metallization lines.

As DI water is spun off from the hydrophobic face of a semiconductorstructure, water droplet size decreases. Any portion of the DI waterdroplet that is not pure water is attracted to the hydrophobic surfacesof the semiconductor structure, while the water portion is repelled.Because the water droplets become exceedingly small, dissolvedimpurities are more strongly attracted to the hydrophobic surfaces ofthe semiconductor structure than they are to remain in solution withinthe water droplet.

The Marangoni drying technique reduces water spotting that is incidentto spin drying. In the Marangoni drying technique, a chemically treatedsemiconductor structure is DI water rinsed, transferred to the Marangonidryer, immersed in a DI water bath, and drawn through an isopropylalcohol (IPA) layer that rests on the surface of the DI water bath. Inthe Marangoni technique, the forces that attract impurities to exposedhydrophobic semiconductor structure surfaces are balanced by the bulk ofthe water in the relatively pure DI water bath that tends to keep theimpurities in solution. When employing the Marangoni drying technique,the DI water and its impurities are entrained beneath the water-IPAinterface while the semiconductor structure is drawn through theinterface.

Marangoni drying reduces water spotting, but it does not ameliorateoxidative contamination that occurs upon a semiconductor structureduring transfer of the semiconductor structure from the DI water rinsingvessel to the dryer. Thus, elimination of the deleterious effects ofwater spotting may be overshadowed by contamination of the semiconductorstructure experienced simply during transfer from one vessel to another.

Because a Marangoni dryer may have moving parts, the function of whichis to draw a wafer boat out of a DI water bath, the possibility ofparticulate contamination arises, which contamination is caused byabrasion of surfaces on the moving parts.

What is needed is a method of rinsing and drying semiconductorstructures particularly hydrophobic semiconductor structures, in such away as to substantially eliminate oxide contamination incident tosemiconductor structure transfer from vessel to vessel and by waterspotting incident to spin drying. What is also needed is a device thatwill accomplish the inventive method while simplifying the Marangonitechnique and equipment.

SUMMARY OF THE INVENTION

The present invention relates to a method of cleaning and dryingsemiconductor structures. The present invention also relates to a methodof using a conventional gas etch/rinse vessel, or a conventional dryervessel, The present invention also relates to an apparatus thataccomplishes the inventive method. The present invention reduces thelikelihood of oxide contamination and the like, as well as the incidenceof water spotting.

In a first embodiment of the present invention, a semiconductorstructure is placed into a first treatment vessel for a chemicaltreatment. Following the chemical treatment, the semiconductor structureis transferred directly from the first treatment vessel to a secondtreatment vessel. The semiconductor structure is rinsed with DI water inthe second treatment vessel. Next, the second treatment vessel isflooded with DI water to form a DI water bath. The second treatmentvessel may also be optionally flooded with a gas that is inert to theambient, such as nitrogen, to form in the second treatment vessel aninert atmosphere. The inert gas forming the inert atmosphere is intendedherein to mean a gas that does not substantially react with or otherwisecontaminate the semiconductor structure or the vessel in which the inertatmosphere is formed under the processing conditions set forth herein.The inert atmosphere is maintained during rinsing. Following rinsing, agaseous stream, such as nitrogen, that is laden with IPA vapor is fedinto the second treatment vessel.

After a selected period of time, a layer of IPA has formed upon thesurface of the DI water bath to form an IPA-DI water interface. Thesemiconductor structure is drawn out of the DI water bath at a preferredrate that causes substantially all the DI water, and contaminantstherein, to be entrained beneath the IPA-DI water interface.

In a second embodiment of the present invention, a dry etch isperformed. The process of the second embodiment comprises first placinga semiconductor structure into a gas etch chamber. After placing asemiconductor structure into a gas etch chamber, the gas etch chamber issealed and gas etching of the semiconductor structure commences.Following gas etching, the semiconductor structure is rinsed with DIwater. After rinsing and an optional washing of the semiconductorstructure in the gas etch chamber, the gas etch chamber is purged of anygas that is not inert to the semiconductor structure or to the gas etchchamber. The semiconductor structure is then submerged in DI water byflooding the gas etch chamber, wherein a surface of DI water forms abovethe semiconductor structure. Nitrogen gas laden with IPA vapor isintroduced into the gas etch chamber to form an IPA-DI water interfaceupon the surface of the DI water. Finally, the gas etch chamber isdrained by displacing the DI water bath with more IPA-laden nitrogen. Asthe gas etch chamber is drained at a preferred rate, the IPA-DI waterinterface functions as a dynamic barrier to the DI water andsubstantially “wipes down” the semiconductor structure by substantiallyentraining the DI water, and contaminants therein, beneath the IPA.

In a third embodiment of the present invention, a rinser is retrofitwith a lid and a fail-shut valve. In the third embodiment, the processof chemical treatment is carried out conventionally, but DI waterrinsing and drying both occur within the rinser. Following sufficientrinse cycles, IPA-laden nitrogen is fed into the rinser in a mannersimilar to the method of the second embodiment. Entrainment ofsubstantially all DI water, and contaminants therein, beneath the IPAlayer is accomplished by displacement of the last spray/dump DI watervolume with an IPA-DI water interface as set forth above. In thisembodiment, retrofit rinsers include spray/dump rinsers, overflowrinsers, cascade rinsers, and Marangoni dryers that have been retrofitwith rinsing capabilities.

These and other features of the present invention will become more fullyapparent from the following description and appended claims, or may belearned by the practice of the invention as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the manner in which the above-recited and other advantagesof the invention are obtained, a more particular description of theinvention briefly described above will be rendered by reference tospecific embodiments thereof which are illustrated in the appendeddrawings. Understanding that these drawings depict only typicalembodiments of the invention and are not therefore to be considered tobe limiting of its scope, the invention will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 is a cross-sectional elevational view of a glove valve that canbe installed in a Marangoni dryer, a spray/dump rinser, and other wetprocessing vessels in order to practice the method of the presentinvention.

FIG. 2 is a cross-sectional elevational view of a check valve that canbe installed in a Marangoni dryer, a spray/dump rinser, and other wetprocessing vessels in order to practice the method of the presentinvention.

FIG. 3 is a cross-sectional elevational view of a diaphragm valve thatcan be installed in a Marangoni dryer, a spray/dump rinser, and otherwet processing vessels in order to practice the method of the presentinvention.

FIG. 4 is an elevational side view of a treatment vessel used in themethod of the present invention in which fail-shut valves or simple gatevalves are used to allow draining of the treatment vessel according tothe method of the present invention.

FIG. 5 is an elevational side view of a sealed overflow rinse vesselused in the present invention in which a vessel wall is illustrated astransparent.

FIG. 6 is an elevational side view of a sealed spray/dump rinse vesselused in the present invention in which a vessel wall is illustrated astransparent.

FIG. 7 is an elevational side view of a sealed cascade rinse vessel usedin the present invention in which a vessel wall is illustrated astransparent.

FIG. 8 is an elevational side view of a sealed Marangoni dryer typerinse/dry vessel used in the present invention in which a vessel wall isillustrated as transparent.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a method of cleaning and dryingsemiconductor structures. The present invention also relates to a methodof using a conventional gas etch/rinse vessel, or a conventional dryer,or a conventional rinser in conjunction with the inventive method. Thepresent invention also relates to an apparatus that accomplishes theinventive method. The present invention reduces the likelihood of oxidecontamination or the like, as well as the incidence of water spotting.

Rinsing by the method of the present invention is usually carried outwith DI water. Other rinsing solutions may be used such as aqueoushydrogen peroxide. Drying by the method of the present inventioncomprises forming a substantially continuous layer of a drying liquidupon the upper surface of a DI water bath in which the semiconductorstructure is submerged. Following formation of the substantiallycontinuous layer of the drying liquid, the semiconductor structure isdrawn through the substantially continuous layer of the drying liquid.Both the DI water and contaminants therein are entrained beneath thesubstantially continuous layer of the drying liquid in the DI water bathand are therefore substantially removed from the semiconductorstructure.

The drying liquid comprises a volatile liquid such as IPA. Other dryingliquids are contemplated to be, but need not be, derived from ananhydrous organic vapor, such as acetone, chloroform, methanol, carbontetrachloride, benzene, ethanol, ethyl acetate, hexane, 1-propanol, and2-propanol, and equivalents. By reading the disclosure of the presentinvention and by practicing the present invention, one of ordinary skillin the art will recognize that anhydrous organic liquids or the like maybe used in the method of the present invention. The skilled practitionerwill recognize that, although a water-miscible drying liquid such as IPAmay be used, such liquids are preferred to be more volatile than the DIwater used for rinsing, and such liquids are preferred in that they arenot prone to cause deleterious chemical effects upon the semiconductorstructure.

In order to avoid unwanted oxidation or other contamination incident toambient air exposure that may occur during and after rinsing, the methodof the present invention comprises filling the rinsing vessel with a gasthat will not react detrimentally with the semiconductor structure. Thegas preferably will be inert to both the semiconductor structure and tothe rinsing vessel, such as nitrogen. Other gases that may be usedinclude all the noble gases, methane, ethane, and the like. Other gasesmay include the drying liquid in vapor form. The preferred gas, if a gasis used, is nitrogen.

In a first embodiment of the present invention, a semiconductorstructure is placed into a first treatment vessel and chemicallytreated. Chemical treatment may be any number of treatments such asrinsing the semiconductor structure in an aqueous HF solution,performing an HF dry etch on the semiconductor structure, performing abuffered oxide etch on the semiconductor structure, performing apolysilicon etch on the semiconductor structure, other wet or dryetching processes, photoresist stripping, or RCA cleaning. In an exampleof the first embodiment, an HF rinse is carried out in which aqueous HFcontacts the semiconductor structure and is optionally filtered andrecirculated. The aqueous HF is discarded after a number of usesdepending upon the specific application.

Following the chemical treatment step, a rinsing step is carried outusually by transferring the semiconductor structure to a secondtreatment vessel and performing a DI water rinse. DI water rinsingvessels are known in the art such as a cascade rinser, an overflowrinser, a spray/dump rinser, a spin/rinse dryer, an etcher/rinser, andothers. In the first embodiment of the present invention, the rinsingvessel is omitted. The semiconductor structure is transferred directlyfrom the first treatment vessel to a second treatment vessel, rinsed inthe second treatment vessel, and then dried. In this first embodiment ofthe present invention, the semiconductor structure is transferred froman HF-last cleaning vessel to a Marangoni dryer that has been retrofitwith means for contacting the semiconductor structure with DI water,such as with spray nozzles for rinsing the semiconductor structure.

In the first example of the first embodiment of the present invention,most of the hydrophobic surfaces of the semiconductor structure arehydrogen terminated, e.g. M—H, where M represents Si, Al, Al alloys, andother metals. About ten to twenty percent of the bonds, however, are M—Finstead of the preferred M—H. Because significant oxidation occurs onlyafter the rinsing, and because significant water spotting occurs onlyduring spin drying or post-rinse (pre-dry) atmospheric exposure,exposing the semiconductor structure to the ambient by transferring itfrom an HF rinsing treatment vessel to a rinse/dry treatment vesselunder conventional clean room conditions results in some contaminationof the semiconductor structure. The inventive method, therefore, doesnot expose the semiconductor structure to ambient air after rinsing.

The second treatment vessel is flooded with an inert gas such asnitrogen to create an inert atmosphere, and the inert atmosphere ismaintained during rinsing. Maintaining an inert atmosphere preventsunwanted oxidation caused by oxygen contact with freshly broken M—Fbonds that occur during rinsing. Alternatively, no inert gas per se isused, but rather the second treatment vessel is flooded with ananhydrous organic vapor such as with IPA vapor. Rinsing is carried outin such a way that the IPA vapor is not substantially flushed from thesecond treatment vessel.

Rinsing is commenced within the second treatment vessel. Followingappropriate rinsing, the second treatment vessel is optionally cleanedand a DI water bath is formed in the second treatment vessel. A nitrogenstream that is laden with IPA vapor is fed into the second treatmentvessel. Alternatively, an IPA stream with no nitrogen or other inert gasacting as a carrier is fed to the second treatment vessel. After apreferred period of time, a layer of IPA has formed upon the surface ofthe DI water bath to form an IPA-DI water interface. When a sufficientlayer of IPA vapor has formed upon the surface of the DI water bath, thesemiconductor structure is drawn out of the DI water bath at a rate thatallows substantially all DI water, and contaminants therein, on thesemiconductor structure to be entrained beneath the IPA-DI waterinterface. Impurities in the DI water bath are substantially allretained in the DI water bath as the semiconductor structure is drawnthrough the IPA-DI water interface. By this method, unwanted oxidationincident to ambient exposure of the semiconductor structure isminimized, and unwanted water spotting incident to spin drying andincident to post rinse atmospheric exposure is eliminated.

In a second embodiment of the present invention, the chemical treatmentis an HF gas etch, by way of non-limiting example. Other etching may becarried out, such as wet or dry etching. Following the chemicaltreatment, a DI water rinse followed by drying is carried out.Single-chamber HF gas etching may be done, or multiple-chamber etchingmay be done by using an apparatus such as that described in U.S. Pat.No. 5,089,084 issued to Chhabra et al., the disclosure of which isincorporated herein by specific reference.

The process of the second embodiment comprises first placing asemiconductor structure into a gas etch chamber. The gas etch chamber issealed and gas etching of the semiconductor structure commences.Following gas etching, the semiconductor structure is rinsed with DIwater in an inert atmosphere, and optionally washed in the gas etchchamber. The semiconductor structure is then submerged in DI water byflooding the gas etch chamber with DI water, wherein a surface of DIwater forms above the semiconductor structure. An inert carrier gas,such as nitrogen gas laden with IPA vapor, is introduced into the gasetch chamber to form an IPA-DI water interface upon the surface of theDI water. Alternatively, an IPA vapor without an inert carrier gas isintroduced into the gas etch chamber to form an IPA-DI water interfaceupon the surface of the DI water. Finally, the gas etch chamber isdrained by displacing the DI water bath with more IPA-laden nitrogen, bymore IPA alone, or by nitrogen alone, whereby the IPA layer entrains theDI water, and contaminants therein, beneath itself while the DI water isdraining or being displaced.

The method of draining the gas etch chamber by displacing the DI waterbath with a gas or a vapor, or both, can be accomplished by installingan effluent valve, as seen in FIGS. 1-3, in the gas etch chamber at alevel below the lowest portion of the semiconductor structure. Apreferred valve is one that is fail-shut, but that opens by sufficientpositive pressure on the gas etch chamber side of the valve. In FIG. 1,a glove valve 10 is installed within an effluent pipe 12 that can beinstalled in a gas etch chamber according to the second embodiment ofthe present invention. Glove valve 10 comprises a stopper 14 that ispart of a valve housing 26 that is part of effluent pipe 12. Stopper 14is attached to a valve shaft 16 that moves in directions V. Valve shaft16 may be attached to a spring or some other device that providesstopper 14 with a selected resistance against allowing an effluent flowF therethrough. The selected resistance can be chosen depending upon thespecific application.

In an example of the second embodiment of the present invention, apreferred IPA-DI water interface thickness is selected to optimizeentrainment beneath the IPA-DI water interface of all dissolvedimpurities contained within the DI water bath. A selected resistance isset to resist movement of valve shaft 16 caused by pressure against thegas etch chamber side of stopper 14. The selected resistance allows aspecific pressure within the gas etch chamber, such that the IPA-DIwater interface will have a preferred thickness, and such thatdisplacement of the DI water bath is accomplished only by furtherfeeding of the gases, such as IPA-laden nitrogen, IPA alone, or nitrogenalone, to the gas etch chamber.

Another valve scheme, seen in FIG. 2, includes a check valve 18 thatcomprises a ball 28 that rests in a fail-shut mode against asphere-contoured valve seat 20. One advantage of check valve 18 is thatno moving part must breach valve housing 26, such as is seen in FIG. 1where valve shaft 16 is required for a glove valve or a diaphragm valve.With no breach of valve housing 26, the possibility of abraded partscaused by dynamic frictional contact of valve shaft 16 against valvehousing 26 is eliminated.

Check valve 18 can be configured within valve housing 26 such that aselected clearance 22 limits how high ball 28 of check valve 18 mayrise, and therefore how large an effluent opening allows effluent flow Fto pass through. It can be seen in FIG. 2 that clearance 22 could beconfigured to allow ball 28 of check valve 18 to move less than onediameter thereof, or to move greater than one diameter thereof. It willbe appreciated by one of ordinary skill in the art that using thepresent disclosure as a guide, clearance 22 may be adjusted within asingle valve housing by placing a screw or piston above ball 28 of checkvalve 18 to adjustably limit its upward motion.

Thus, for a process that merits well-defined process parameters and thatis part of a high-volume fabrication, clearance 22 of valve housing 26for check valve 18 may be unadjustable. On the other hand, for anapparatus that is used for various processes that require selecteddissimilar conditions, valve housing 26 for check valve 18 may have anadjustable clearance 22.

Another valve scheme is a diaphragm valve 30 illustrated in FIG. 3.Diaphragm valve 30 comprises a flexible diaphragm 24 that is connectedto valve shaft 16 similarly to glove valve 10. It can be appreciated byone of ordinary skill in the art that the function of the valvesillustrated in FIGS. 1-3 can also be accomplished by a simple gooseneck, wherein the height of the goose neck may be selected to allowpressures that optimize the IPA-DI water interface or other processingparameters as the gas etch chamber is drained.

The process of entraining DI water and thereby substantially removing DIwater, and contaminants therein, from the semiconductor structure by themethod of the present invention may be accomplished in the secondembodiment by a rapid displacement of the DI water bath such that theIPA layer “wipes down” the semiconductor structure in a substantiallycontinuous stroke. A rapid displacement may be accomplished, forexample, by pushing IPA-laden nitrogen from a piston that displaces avolume approximately equal to the volume of the gas etch chamber.

Where a rapid displacement of the DI water bath from the gas etchchamber is not a preferred variation of draining the gas etch chamber,IPA-laden nitrogen may be fed to the gas etch chamber by conventionallyused equipment and methods such as those used in a STEAG® Marangonidryer.

A third embodiment of the present invention comprises a retrofitspray/dump rinser with a rinser-sealable lid 54 and a valve 34 such asthose depicted in FIGS. 4-6. In the third embodiment, the process ofchemical treatment is carried out conventionally, but DI water rinsingand drying both occur within the rinser. Following sufficient spray/dumpcycles, IPA-laden nitrogen or the like is fed into the rinser in amanner similar to the method of the second invention. Removal of DIwater from the semiconductor structure comprises displacement of thelast spray/dump DI water volume by forming an IPA-DI water interface asset forth above.

The artisan will appreciate that other rinsers may be retrofit topractice the method of the present invention. For example, an overflowrinser or a cascade rinser may be retrofit, as well as spinnerrinser/dryers. FIG. 5 illustrates an elevational side view of anoverflow rinser 40 that has been retrofit with a lid 54, a vapor-gasinlet 52, a semiconductor structure holder 50, and at least onefail-shut valve 34 or a goose neck. During the process of passing anIPA-DI water interface across a semiconductor structure 56, IPA-ladennitrogen gas or the like is fed through vapor-gas inlet 52 whileinfluent DI water that normally enters from below overflow rinser 40 isshut off.

FIG. 6 illustrates an elevational side view of a retrofit cascade rinser42 in which semiconductor structure 56 is substantially batch treatedinstead of counter-current treated. Influent DI water flows in thedirection F and spills over weirs 48. After sufficient rinsing, suchthat semiconductor structure 56 contacted with the DI water that isabout to exit cascade rinser 42 is substantially as thoroughly rinsed assemiconductor structure 56 contacted with the first influent DI water,influent DI water is shut off and IPA-laden nitrogen gas or the like isfed through vapor-gas inlet 52. Fail-shut valves 34 are opened and thepressure of influent IPA-laden nitrogen gas that is fed throughvapor-gas inlet 52 displaces all DI water contained within cascaderinser 42.

Draining each stage in cascade rinser 42 may require that fail-shutvalve 34 in the deepest stage needs to open first. DI water then drainsfrom the deepest stage until the DI water depth in the deepest stagematches that of the next deepest stage, at which point fail-shut valve34 in that stage opens, and so forth for each stage.

Another method of assuring uniform draining of each stage relative tosemiconductor structures 56 is to set semiconductor structures 56 uponracks (not shown). By placing semiconductor structures 56 upon racks,the semiconductor structure 56 in the deepest stage will have completelysurfaced before all DI water has exited from the shallowest stage.

FIG. 7 illustrates an elevational side view of a spray/dump rinser 38that has been retrofit with sealable lid 54 and vapor-gas inlet 52. Inthe method of the present invention, the normal spray/dump cycle iscarried out in an inert atmosphere that may be supplied throughvapor-gas inlet 52. The final flooding of spray/dump rinser 38 comprisesforming an IPA layer upon the DI water bath and either drawingsemiconductor structure 56 through the IPA surface, or draining the DIwater bath as set forth above such that the IPA surface passes acrosssemiconductor structure 56.

FIG. 8 illustrates an elevational side view of a Marangoni type dryer 46in which semiconductor structures 56 are held in semiconductor structureholder 50. In the method of the present invention, rinsing is carriedout within Marangoni type dryer 46 in an inert atmosphere. The methodconcludes by drawing semiconductor structure 56 through an IPA layer 58,or by draining the DI water bath such that IPA layer 58 passes acrosssemiconductor structure 56. As semiconductor structure 56 and IPA layer58 pass each other, the DI water bath, and contaminants therein, isentrained beneath IPA layer 58 such that substantially all DI water isremoved from semiconductor structure 56.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims and their combination in whole or in part ratherthan by the foregoing description. All changes that come within themeaning and range of equivalency of the claims are to be embraced withintheir scope.

What is claimed and desired to be secured by United States LettersPatent is:
 1. A method of cleaning a semiconductor structure comprising:positioning a semiconductor structure within an at least substantiallyenclosed treatment vessel; performing an etching process on saidsemiconductor structure within said treatment vessel; substantiallyfilling said treatment vessel with a gas inert to said semiconductorstructure and inert to said treatment vessel creating an atmosphere ofinert gas inside said treatment vessel; rinsing said semiconductorstructure with DI water in said atmosphere of inert gas; submerging saidsemiconductor structure in a DI water bath in said treatment vesselhaving said DI water bath forming a surface with said gas; forming acontinuous layer of a liquid upon said surface of said DI water bath;contacting substantially all of said semiconductor structure with saidcontinuous layer of said liquid; and entraining said DI water bath belowsaid continuous layer of said liquid.
 2. The method of cleaning asemiconductor structure according to claim 1, wherein said continuouslayer of said liquid comprises an anhydrous liquid.
 3. The method ofcleaning a semiconductor structure according to claim 1, furthercomprising, prior to rinsing said semiconductor structure with DI waterbath, rinsing said semiconductor structure in an aqueous HF solution. 4.The method of cleaning a semiconductor structure according to claim 1,wherein said etching process includes performing a polysilicon etch onsaid semiconductor structure.
 5. The method of cleaning a semiconductorstructure according to claim 1, wherein said gas comprises nitrogen. 6.The method of cleaning a semiconductor structure according to claim 1,wherein said continuous layer of said liquid comprises isopropyl alcoholthat is supplied to said treatment vessel in a gaseous nitrogen carrier.7. The method of cleaning a semiconductor structure according to claim1, wherein said contacting substantially all of said semiconductorstructure with said continuous layer of said liquid comprises drawingsaid semiconductor structure through said continuous layer of saidliquid.
 8. The method of cleaning a semiconductor structure according toclaim 1, wherein contacting substantially all of said semiconductorstructure with said continuous layer of said liquid comprises drainingsaid treatment vessel.
 9. The method of cleaning a semiconductorstructure according to claim 8, wherein said draining said treatmentvessel comprises displacing said DI water bath by creating a positivepressure within said treatment vessel with an anhydrous organic liquidin an inert gas carrier, whereby said DI water bath is displaced fromsaid treatment vessel through at least one valve.
 10. The method ofcleaning a semiconductor structure according to claim 8, wherein saiddraining said treatment vessel comprises opening a valve, whereby saidDI water bath drains from said treatment vessel by gravity.
 11. Themethod of cleaning a semiconductor structure according to claim 1,wherein said treatment vessel comprises a spray/dump rinser.
 12. Themethod of cleaning a semiconductor structure according to claim 1,wherein said treatment vessel comprises a cascade rinser.
 13. The methodof cleaning a semiconductor structure according to claim 1, wherein saidtreatment vessel comprises an overflow rinser.
 14. The method ofcleaning a semiconductor structure according to claim 1, wherein saidtreatment vessel comprises a Marangoni dryer.
 15. A method of cleaning asemiconductor structure comprising: selecting a chemical etching processselected from a group consisting of rinsing said semiconductor structurein an aqueous HF solution, performing an HF dry etch on saidsemiconductor structure, and performing a polysilicon etch on saidsemiconductor structure; performing said chemical etching process uponsaid semiconductor structure within an at least substantially enclosedtreatment vessel; substantially filling said treatment vessel with a gasthat is inert to said semiconductor structure and to said treatmentvessel; providing an inert gas atmosphere inside said treatment vessel;rinsing said semiconductor structure with DI water in said inert gasatmosphere; submerging said semiconductor structure in a DI water bathin said treatment vessel; forming a surface between said DI water bathand said gas; forming a liquid layer at said surface formed by said DIwater bath surface and gas; and separating said semiconductor structurefrom said DI water bath such that substantially all of saidsemiconductor structure passes through said liquid layer.
 16. The methodof cleaning a semiconductor structure according to claim 15, whereinsaid gas comprises nitrogen.
 17. The method of cleaning a semiconductorstructure according to claim 15, wherein said liquid layer comprisesisopropyl alcohol conveyed to said treatment vessel in a nitrogencarrier.
 18. The method of cleaning a semiconductor structure accordingto claim 15, wherein said separating said semiconductor structure fromsaid DI water bath comprises drawing said semiconductor structure out ofsaid DI water bath.
 19. The method of cleaning a semiconductor structureaccording to claim 15, wherein said separating said semiconductorstructure from said DI water bath comprises draining said treatmentvessel.
 20. The method of cleaning a semiconductor structure accordingto claim 19, wherein said draining said treatment vessel comprisesdisplacing said DI water bath by purging said treatment vessel with ananhydrous organic liquid in an inert gas carrier, whereby said DI waterbath is displaced from said treatment vessel through at least one valve.21. The method of cleaning a semiconductor structure according to claim19, wherein said draining said treatment vessel comprises opening avalve, whereby said DI water bath drains by gravity.
 22. The method ofcleaning a semiconductor structure according to claim 15, wherein saidtreatment vessel is selected from a group consisting of a spray/dumprinser, a cascade rinser, an overflow rinser, and a Marangoni dryer. 23.A method of cleaning a semiconductor structure comprising: performing achemical reaction wet etching upon said semiconductor structure within asingle compartment of an at least substantially enclosed vessel; purgingthe single compartment of said vessel with a gas; forming an inert gasatmosphere in the single compartment of said vessel, said gas formingsaid inert gas atmosphere being inert to said semiconductor structureand to said vessel; contacting said semiconductor structure with DIwater; removing from said semiconductor structure chemicals from saidchemical reaction wet etching; maintaining said inert gas atmosphere inthe single compartment of said vessel by filling the single compartmentof said vessel using DI water, submerging said semiconductor structurein the single compartment of said vessel and contacting said DI waterwith said inert gas; providing an anhydrous organic vapor selected froma group consisting of acetone, chloroform, methanol, carbontetrachloride, benzene, ethanol, ethyl acetate, hexane, 1-propanol, and2-propanol, and wherein said anhydrous organic vapor contacts a surfaceof said DI water to form a layer of said anhydrous organic liquidthereon; displacing said inert gas atmosphere with said anhydrousorganic vapor, said anhydrous organic vapor contacting a surface of saidDI water; forming a layer of said anhydrous organic liquid upon contactof said surface of said DI water by said anhydrous organic vapor; anddrawing said semiconductor structure out of said DI water through saidlayer of said anhydrous organic liquid substantially all of saidsemiconductor structure contacting said layer of said anhydrous organicliquid.
 24. The method as defined in claim 23, wherein said anhydrousorganic vapor is conveyed to said vessel in an inert gas carrier. 25.The method as defined in claim 24, wherein said inert gas carrier isselected from the group consisting of nitrogen, the noble gases,methane, and ethane.
 26. The method as defined in claim 23, wherein saidchemical reaction wet etch upon said semiconductor structure comprises aprocess selected from a group consisting of rinsing said semiconductorstructure in an aqueous HF solution, and performing a polysilicon etchon said semiconductor structure.